President Trump announced Saturday morning that he planned to release the tens of thousands of never-before-seen documents left in the files related to President John F. Kennedy’s assassination held by the National Archives and Records Administration.

“Subject to the receipt of further information, I will be allowing, as President, the long blocked and classified JFK FILES to be opened,” Trump tweeted early Saturday.

Experts have been speculating for weeks about whether Trump would disclose the documents. The 1992 Kennedy Assassination Records Collection Act required that the millions of pages, many of them contained in CIA and FBI documents, be published in 25 years — by Thursday. Over the years, the National Archives has released most of the documents, either in full or partially redacted.

But one final batch remains, and only the president has the authority to extend the papers’ secrecy past the deadline.

In his tweet, Trump seemed to strongly imply he was going to release all the remaining documents, but the White House later said that if other government agencies made a strong case not to release the documents, he wouldn’t.

“The president believes that these documents should be made available in the interests of full transparency unless agencies provide a compelling and clear national security or law enforcement justification otherwise,” the White House said in a statement Saturday.

In the days leading up to Trump’s announcement, a National Security Council official told The Washington Post that government agencies were urging the president not to release some of the documents. But Trump’s longtime confidant Roger Stone told conspiracy theorist Alex Jones of Infowars this week that he personally lobbied Trump to release all of the documents.

Stone also told Jones that CIA Director Mike Pompeo “has been lobbying the president furiously not to release these documents.”

Some Republican lawmakers have also been urging Trump for a full release. Earlier this month, Rep. Walter B. Jones (R-N.C.) and Sen. Charles E. Grassley (R-Iowa), chairman of the Senate Judiciary Committee, brought forward resolutions calling on Trump to “reject any claims for the continued postponement” of the documents.

Though Kennedy assassination experts say that they do not think the last batch of papers contains any major bombshells, the president’s decision to release the documents could heighten the clarity around the assassination, which has fueled so many conspiracy theorists, including Trump.

In May 2016, while on the presidential campaign trail, Trump gave an interview to Fox News strongly accusing the father of GOP primary opponent Sen. Ted Cruz (R-Tex.) of consorting with Kennedy assassin Lee Harvey Oswald right before the shooting.

Some Kennedy assassination researchers think that the trove could shed light on a key question that President Lyndon B. Johnson tried to unsuccessfully put to rest in 1963: Did Oswald act alone, or was he aided or propelled by a foreign government?

The records are also said to include details on Oswald’s activities while he was traveling in Mexico City in late September 1963 and courting Cuban and Soviet spies, as well as the CIA’s personality profiles written of Oswald after the assassination.

But some experts fear the history that may be lost forever in unreadable documents in the trove. One listed as “unintelligible” is a secret communication from the CIA to the Office of Naval Intelligence about Oswald in October 1963 — weeks before the assassination. Oswald had been honorably discharged from the Marine Corps in 1959, but it was later changed to a dishonorable discharge. He was outraged and made threats late in 1963 when he learned the military had rejected his appeal of its decision.

Phil Shenon, who wrote a book about the Warren Commission, the congressional body that investigated Kennedy’s killing, said he was pleased with Trump’s decision to release the documents. But he wonders to what degree the papers will ultimately be released.

“It’s great news that the president is focused on this and that he’s trying to demonstrate transparency. But the question remains whether he will open the library in full — every word in every document, as the law requires,” Shenon said. “And my understanding is that he won’t without infuriating people at the CIA and elsewhere who are determined to keep at least some of the information secret, especially in documents created in the 1990s.”

There are about 3,100 previously unreleased files that hold tens of thousands of pages of new material. The National Archives also has another 30,000 pages with information that has been disclosed before, but only partially and with redactions.

Jefferson Morley, a former Post reporter who has studied the Kennedy assassination records for years, said that the last tranche of material is also intriguing because it contains files on senior CIA officials from the 1960s — officers well aware of Oswald’s activities in the days before the assassination.

He specifically pointed to the files of former CIA officers William K. Harvey and David Phillips. Morley said Harvey led the agency’s assassinations operations and feuded constantly with Kennedy’s brother, Robert F. Kennedy, over the administration’s crisis with Cuba. Phillips, Morley said, oversaw the agency’s operations against Cuban President Fidel Castro and was deeply familiar with the CIA’s surveillance of Oswald in Mexico City.

“What’s in those files could tell us how those men did their jobs,” said Morley, who wrote a 2008 book on the agency’s Mexico City station chief. “There might be stuff on why we were interested in the Cuban consulate, how we surveilled the consulate, how we did our audio work, and how did we recruit spies there? We might understand much better why they were watching Oswald.”